Our studies of velocity and width of Mg I line were based on the
distributions of positions and velocities of migrating dust particles.
These distributions were obtained in our integrations of the orbital
evolution of particles started from different small bodies (asteroids,
comets, trans-Neptunian objects) [Annals of the New York Acad. of Sci.,
2004, 1017, 66-80; Advances in Space Research, 2006, 37, 126-137].
Comparison of our models with the WHAM observations of velocities of
zodiacal dust particles and the mean width of Mg I line made by Reynolds
et al. (ApJ, 2004, 612, 1206-1213) shows that only asteroidal dust
particles cannot explain these observations, and particles produced by
comets, including high-eccentricity comets (such as Comet Encke and
long-period comets), are needed for such explanation. The values of the
exponent in the power law of the distribution of particles with the
distance R from the Sun at R about 1 AU were smaller for asteroidal
particles than those for the measurements of micrometeoroid flux made by
Helios 1 and Pioneer 10. The fraction of particles started from
Encke-type comets is not large (probably, less than 10-15\%) in order to
fit the observational distributions of particles over their distances
from the Sun. Greater velocity amplitudes of velocity - elongation
curves at elongation between 90 and 270 deg usually correspond to
greater mean eccentricities of particles at distance R about 1-3 AU. For
the same mean eccentricities, velocity - elongation plots depend also on
the distributions of particles over their eccentricities. The mean
eccentricity of zodiacal dust particles that better fit the WHAM
observations is estimated to be about 0.5. Results of our studies were
presented in [LPSC, 2006, #1471], and a wider paper will be submitted to
AJ this summer and will be put on astro-ph.